X-Fe (X = Mn, Co, Cu) Prussian Blue Analogue-Modified Carbon Cloth Electrodes for Capacitive Deionization

Capacitive deionization is proven to be a viable resource-efficient alternative to remove dissolved salts from water. Further improvements in electrode materials are, however, necessary to achieve a higher efficiency of water desalination. In this work, X-Fe (X = Mn, Co, Cu) Prussian blue analogues of homogeneous particle sizes were grown on electrically conducting activated carbon cloth electrodes by a simple and facile synthesis process. As two-dimensional/three-dimensional (2D/3D) nanostructured Prussian blue analogue materials present favorable electrochemical behavior and ion-exchange possibilities, they are promising for application in capacitive deionization. The modified carbon cloth electrodes exhibit higher salt adsorption capacity and better charge efficiency compared to those constructed with pristine carbon cloth. Cobalt hexacyanoferrate-modified electrodes show the most stable performance, reaching a salt adsorption capacity of 14.47 mg g–1 at 1.0 V, accompanied by the lowest energy consumption (0.389 kWh m–3). This simple strategy is expected to offer possibilities for designing and synthesizing advanced electrode materials with superior performances for application in capacitive deionization devices.